Yue-Wei Ge

Aristololactams and aporphines from the stems of Fissistigma oldhamii (Annonaceae)

Two aristololactams, aristololactam GI (1) and aristololactam GII (2), and three aporphines, fissistigamide A (3), fissistigamide B (4) and fissistigmine (5), together with nineteen known alkaloids, one flavone and one anthraquinone were isolated from the ethanol extracts of the stems of Fissistigma oldhamii (Annonaceae). Their structures were elucidated primarily by analysis of NMR, IR, UV, MS and CD data. Alkaloid 1 is a chiral aristololactam formed from a phenylpropanoid derivative attached to a 3,4-dihydroxy aristololactam scaffold. The absolute configuration of 1 was determined by comparing experimental and calculated ECD spectra. The anti-inflammatory activity of the crude extracts and the five alkaloids were tested by measuring the amount of TNF-α and IL-6 released from LPS stimulated RAW264 cell via ELISA. The results demonstrated that the CHCl(3)-soluble part and alkaloid 2 exhibited significant anti-inflammatory activity in vitro in both assays.

Effects of Oleanane-Type Triterpene Saponins from the Leaves of Eleutherococcus senticosus in an Axonal Outgrowth Assay

An aqueous extract of Eleutherococcus senticosus leaves exerted a beneficial effect in restoring the neurite outgrowth from Aβ25-35-induced degeneration using an axonal density assay. Subsequent bioassay-guided fractionation afforded seven new oleanane-type triterpene saponins, ezoukoginosides A-G (1-7), along with nine known analogues. The structures of 1-7 were elucidated through chemical and spectroscopic approaches, and their effects on restoring the neurite outgrowth from Aβ25-35-induced degeneration were investigated. The results revealed that hydrophilic oleanane-type saponins substituted with a free carboxylic acid, hydroxy, or formyl group in the aglycone, especially when the oxidation occurred at C-29, not only restrained Aβ25-35-induced degeneration but also restored axonal outgrowth significantly. Compounds 2 (-COOH at C-29) and 3 (-CH2OH at C-29) showed the most potent bioactivity among the isolates.

Molecular ion index assisted comprehensive profiling of B-type oligomeric proanthocyanidins in rhubarb by high performance liquid chromatography-tandem mass spectrometry

AbstractProanthocyanidins (PAs) are major anti-diarrhea constituents in rhubarb, one of the frequently used traditional medicines. However, the phytochemical investigation of PAs in rhubarb was hampered by their strenuous purification and identification. In the present study, aiming to clarify the distribution of PAs in different rhubarb species, a molecular ion index was priorly established according to the structural features of B-type PAs, which led to a series of targeted discovery of oligomeric PAs in rhubarb by the HPLC-ESI-MS/MS method. Totally, 66 oligomeric PAs including 27 dimers, 29 trimers, and 10 tetramers were tentatively identified on the basis of their MS/MS spectra from 28 rhubarb samples derived from 5 Rheum species as R. palmatum, R. tanguticum, R. officinale, R. coreanum, and R. laciniatum. It is noteworthy that 6 propelargonidins, 14 prodelphinidins, and 10 procyanidin-tetramers were identified from rhubarb for the first time. The profiling comparison of these oligomeric PAs in different rhubarb samples was achieved by visualizing their abundance in a heat map, which indicated the dominant PAs in rhubarb were procyanidin-dimer and its galloylated derivatives. Graphical AbstractA molecular ion index was priorly established according to the structural features of B-type PAs, which led to a series of targeted discovery of oligomeric PAs in rhubarb by the HPLC-ESI-MS/MS method.

Secoiridoid glycosides from the root of Gentiana crassicaulis with inhibitory effects against LPS-induced NO and IL-6 production in RAW264 macrophages

The root of Gentiana crassicaulis has been widely used for the treatment of rheumatism, arthralgia, apoplexy, jaundice and diabetes in traditional medicines, and contains secoiridoid glycosides as the main active ingredients. In the present study, five new secoiridoid glycosides, 6′-O-β-d-xylopyranosylgentiopicroside (1) and gentiananosides A–D (2–5), together with 11 known ones were isolated from the MeOH extract of dried roots of G. crassicaulis. Their structures were elucidated on the basis of extensive spectroscopic evidence. Of them, gentiananosides A (2) and B (3) were concluded to be novel secoiridoid glycosides with an ether linkage between C-2′ of the sugar moiety and C-3 of the aglycone. Compounds 1, 4, 5, 7, 8, 12–14 exhibited moderate inhibitory effects against lipopolysaccharide-induced nitric oxide and interleukin-6 (IL-6) production in RAW264 cells, whereas 2 and 15 exhibited moderate inhibitory effects only against IL-6 production.

MS/MS similarity networking accelerated target profiling of triterpene saponins in Eleutherococcus senticosus leaves

The targeted mass information of compounds accelerated their discovery in a large volume of untargeted MS data. An MS/MS similarity networking is advanced in clustering the structural analogues, which benefits the collection of mass information of similar compounds. The triterpene saponins extracted from Eleutherococcus senticosus leaves (ESL), a kind of functional tea, have shown promise in the relief of Alzheimers disease. In this work, a target-precursor list (TPL) generated using MS/MS similarity networking was employed to rapidly trace 106 triterpene saponins from the aqueous extracts of ESL, of which 49 were tentatively identified as potentially new triterpene saponins. Moreover, a compound database of triterpene saponins was established and successfully applied to uncover their distribution features in ESL samples collected from different areas.